With an arrival of age of cloud computing and big data, computing and storage in three core elements (computing, storage, and network) of the Information Communication Technology (ICT) system have been developing toward a direction of cloudization and virtualization. And a rigid network becomes the last obstacle on a way of an ICT system to march toward automatization and software orientation. In order to eliminate bottleneck constraints brought by a traditional network and complete the last piece of puzzle of the ICT system facing openness, a virtualization network, as a future development direction, has attracted more and more industry attentions. The currently popular Software Defined Network (SDN) is a typical virtualization network.
The SDN is an innovative network architecture proposed by a clean slate research group of Stanford University. A core technology OpenFlow of the SDN separates a control plane and a data plane of a network device, standardizes a forwarding device and centralizes the control plane so that all control functions are implemented by programming through the centralized control plane without need of upgrading a forwarding plane, so as to realize a flexible control of network flow and provide a good platform for an innovation of core networks and applications. A core concept of the SDN is that a control operation and a forwarding operation are separated, the forwarding device is standardized and simplified, the control plane is centralized, and all control functions are implemented by programming through the centralized control plane without need of upgrading the forwarding plane.
The SDN has global information, and optimizes at least one path based on the global information, so that a global demand responded slowly is satisfied fast through a new algorithm. The SDN has a uniform computing object and algorithm, which avoids a problem of too large impact on networks caused by upgrading routers one by one. The SDN provides a better application program interface through the definition of software, so that management of networks performed by applications is realized better. At the same time, the SDN simplifies complex requirements for the control plane and a management plane of a device, so that the device concentrates on forwarding, thereby improving a speed of technological innovation.
As an implementation mode of the SDN, an OpenFlow switch transforms an original packet forwarding process completely controlled by a switch or router into a process completed by an OpenFlow switch and a controller together, thereby realizing separation between data forwarding and routing control. The controller controls a flow table in the OpenFlow switch through an interface operation specified in advance, so as to achieve a purpose of controlling data forwarding. Therefore, OpenFlow opens a road of network innovation. The OpenFlow switch is composed of a flow table, a secure channel and an OpenFlow protocol. The network device maintains the flow table and performs forwarding according to the flow table. The flow table is generated, maintained and sent completely by an external controller. Network operators decide what granularity of flows to use. For example, the operators need to route according to a destination Internet Protocol (IP), then it is possible that the destination IP field in the flow table is effective, and the others are wildcard. The flow table is composed of many flow table items, and each flow table item is a forwarding rule. A data packet entering the switch obtains a destination port of forwarding and corresponding operations by querying the flow table.
The SDN or OpenFlow technology is leading a traditional and closed network toward openness. A majority of operators and manufactures have performed corresponding developing and pilot running work, and problems encountered have been posed step by step, and have been being discussed and solved. As one of network forwarding devices in the SDN, a management of a broadband user access device is an important component. A centralized management of users saves a great amount of device resources and maintenance resources, improves utilization rate, and realizes a more flexible manner of management of users. Keep-alive detection and management of the network forwarding device are realized from an SDN controller, but a management of a single user becomes a problem needing to be mainly solved. Tens of thousands and hundreds of thousands of users are carried on each network forwarding device. If a keep-alive detection and other management functions of the users are also realized by the controller, a great amount of controller resources and massive bandwidth are wasted, and even the normal running of network services is influenced.
Aiming at a problem in the related art that a great amount of resources are wasted in management of UE, an effective solution has not been provided yet.